Modern aircraft, such as large passenger jets, need to operate at various speeds, including a lower speed during take-off and landing and higher speed during cruise. At lower speeds, additional lifting surfaces, also known as high-lift devices such as a trailing edge flap, are sometimes needed to generate the required lift. These additional lifting surfaces are often designed to be stowed at higher speed to minimize the drag at cruising speed and deployed when needed at lower speed during takeoff and landing. When the various lifting surfaces are deployed, their shape and relative motion are designed to generate the lift together efficiently.
During flight, such as cruise conditions, a wing and a trailing edge flap experience loads which cause the wing and the flap to bend and twist. The internal structural design of the wing and flap differ. Further, bending loads from the wing are transferred to the flap at discrete locations, such as the flap support mechanism that allows the flap to be deployed and/or deflected. Because the internal structures are different and the load distributions differ, the wing and flap bend and twist differently from one another during flight.
The mismatch in the deflection and twist between the wing and the flap can cause geometry variations that reduce aerodynamic performance of the wing. This issue can be resolved by mechanically forcing the flap into a certain shape. However, mechanical solutions introduce weight penalties and additional costs, which are undesirable. In view of the above, methods and apparatus are needed that reduce geometry variations between the wing and the flap as a result of different loading and structural conditions during flight.